Toluene degradation by heterogeneous photocatalysis assisted with ozone in a tubular reactor: analysis over the reactor length

2021 ◽  
Author(s):  
Bárbara Maria Borges Ribeiro ◽  
Renato Carajelescov Nonato ◽  
Tânia Miyoko Fujimoto ◽  
Bianca Gvozdenovic Medina Bricio ◽  
Ursula Luana Rochetto Doubek ◽  
...  
Keyword(s):  
Tubular Reactor ◽  
Heterogeneous Photocatalysis ◽  
Toluene Degradation ◽  
Reactor Length

Modeling of a Fixed-Bed Reactor for the Production of Phthalic Anhydride

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Amir Rahimi ◽  
Sogand Hamidi
Keyword(s):  
Phthalic Anhydride ◽  
Fixed Bed ◽  
Tubular Reactor ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Conversion Degree ◽  
Reactor Length ◽  
Reactor Temperature ◽  
Reported Data ◽  
Reactor Pressure

In this study, the performance of a fixed–bed tubular reactor for the production of phthalic anhydride is mathematically analyzed. The conversion degree and reactor temperature values are compared with the measured one in a tubular reactor applied in Farabi petrochemical unit in Iran as well as reported data in the literature for a pilot plate. The comparisons are satisfactory. The effects of some operating parameters including reactor length, feed temperature, reactor pressure, and existence of an inert in the catalytic bed are investigated. The optimum value of each parameter is determined on the basis of the corresponding operating conditions.

scholarly journals Optimization of Pd Membrane Reactor for Direct Oxidation of Aromatic Compounds

2011 ◽  
Vol 11 (1) ◽  
pp. 8
Author(s):  
Milad Rasouli ◽  
Sahar Chitsazan ◽  
Mohammad Hossein Sayyar ◽  
Nakisa Yaghobi ◽  
Babak Bozorgi
Keyword(s):  
Fluid Dynamic ◽  
Active Oxygen Species ◽  
Tubular Reactor ◽  
Direct Oxidation ◽  
Design And Optimization ◽  
Reactor Length ◽  
Length Increase ◽  
Principal Reaction ◽  
Complex Chemical Reactions ◽  
Geometrical Factors

Computational fluid dynamic has already become a widely used and indispensable design and optimization tool in many technical areas. In the present work, the CFD simulations have been coupled with complex chemical reactions to model a membrane tubular reactor which is used to produce phenol from benzene in the vapor phase. Hydrogen dissociates on the palladium layer and reacts with oxygen to give active oxygen species, which attack benzene to produce phenol. In principal, reaction occurs in the surface of palladium and conversion of benzene is increased by changing the length and diameter of the Pd coated PSS tubes. The reactor length and diameter are two geometrical factors which are concerned in the present study. Although increasing the reactor length increase the conversion of benzene to phenol but the concentration of the phenol start to decrease. Based on the data provided by the experiments, a mathematical model has been constructed to conduct a simulation which leads us to an optimum design of a new tubular membrane micro-reactor.

Radiation Field in an Annular Photocatalytic Reactor by the P1 Approximation

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Sergio A Cuevas ◽  
Camilo A Arancibia-Bulnes ◽  
Benito Serrano
Keyword(s):  
Advanced Oxidation Processes ◽  
Scaling Up ◽  
Quantitative Agreement ◽  
Heterogeneous Photocatalysis ◽  
Reactor Wall ◽  
Photocatalytic Reactor ◽  
Oxidation Processes ◽  
Reactor Length ◽  
Radiation Transmission ◽  
Theoretical Results

Heterogeneous photocatalysis with titanium dioxide TiO2 is an advanced oxidation processes that uses ultraviolet radiation to carry out reactions leading to the degradation of polluting agents in water. For the development and scaling up of efficient photocatalytic processes it is important to model the transport of radiation in the reactor volume, because it affects the photo reaction. In the present work we have used the P1 approximation of radiative transfer theory to evaluate radiation distributions inside a specific annular photocatalytic reactor known as Photo CREC–Water II. The reactor consists of two concentric tubes with a TiO2/water suspension flowing axially in the annular space between them, and a lamp at the center of the inner tube. The theoretical results are compared with experimental data from measurements of radiation transmission through several observation windows in the external reactor wall. In general the model describes the observed experimental results well. Due to the nature of the employed approximation a good quantitative agreement is possible only for suspensions with a large optical depth. For small optical depths the agreement is adequate only for the central portion of the reactor length.

scholarly journals Analysis of the dynamics of the system of nonlinear differential equations describing a tubular reactor

2017 ◽  
Author(s):  
◽  
Busuyi Ojo Adebayo
Keyword(s):  
Activation Energy ◽  
Flow Reactor ◽  
Nonlinear Differential Equations ◽  
Tubular Reactor ◽  
Damkohler Number ◽  
Continuous Stirred Tank Reactor ◽  
Three Solutions ◽  
Damköhler Number ◽  
Reactor Length ◽  
Parameter Values

A characterization of the solution(s) of nonlinear boundary value problems (BVPs) arising from a class of chemical reactions occurring in a adiabatic tubular reactor when the mass and thermal Peclet numbers are different is performed. Results show that for large Peclet numbers and activation energy, and for sufficiently small Damkohler number and reactor length, the solution to the BVP is unique. While for small Peclet numbers and activation energy, and for large Damkohler number and reactor length, there exist at least three solutions to the BVP. The conclusion is that the number of solution (s) for the BVP depends on the choice of parameter values. Likewise, the first set of parameter values listed above models the adiabatic plug flow reactor, while the other parameter set models the adiabatic continuous stirred tank reactor.

Factors Affecting the lnteraction of Tissue Factor/Factor Vll with Factor X in a Heterogeneous Tubular Reactor

1991 ◽  
Vol 65 (02) ◽  
pp. 139-143 ◽  
Author(s):  
Cynthia H Gemmell ◽  
Vincet T Turitto ◽  
Yale Nemerson
Keyword(s):  
Steady State ◽  
Tissue Factor ◽  
Factor Viia ◽  
Transmembrane Protein ◽  
Strong Association ◽  
Tubular Reactor ◽  
Factor Xa ◽  
Phospholipid Bilayer ◽  
Factor Vii ◽  
Factor X

SummaryA novel reactor recently described for studying phospholipiddependent blood coagulation reactions under flow conditions similar to those occurring in the vasculature has been further charactenzed. The reactor is a capitlary whose inner wall is coated with a stable phospholipid bilayer (or two bilayers) containing tissue factor, a transmembrane protein that is required for the enzymatic activation of factor X by factor VIIa. Perfusion of the capillary at wall shear rates ranging from 25 s−1 to 1,200 s−1 with purified bovine factors X and VIIa led to steady state factor Xa levels at the outlet. Assay were performed using a chromogenic substrate, SpectrozymeTMFXa, or by using a radiometric technique. In the absence of Ca2+ or factor VIIa there was no product formation. No difference was noted in the levels of factor Xa achieved when non-activated factor VII was perfused. Once steady state was achieved further factor Xa production continued in the absence of factor VIIa implying a very strong association of factor VIIa with the tissue factor in the phospholipid membrane. In agreement with static vesicle-type studies the reactor was sensitive to wall tissue factor concentration, temperature and the presence of phosphatidylserine in the bilayer.

Pyrolysis of brown algae (Bifurcaria Bifurcata) in a stainless steel tubular reactor: From a review to a case study

2018 ◽  
Vol 14 (1) ◽  
pp. 31-60 ◽  
Author(s):  
M. Y. Guida ◽  
F. E. Laghchioua ◽  
A. Hannioui
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Flow Rate ◽  
Brown Algae ◽  
Tubular Reactor ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Bifurcaria Bifurcata ◽  
Bio Oil

This article deals with fast pyrolysis of brown algae, such as Bifurcaria Bifurcata at the range of temperature 300–800 °C in a stainless steel tubular reactor. After a literature review on algae and its importance in renewable sector, a case study was done on pyrolysis of brown algae especially, Bifurcaria Bifurcata. The aim was to experimentally investigate how the temperature, the particle size, the nitrogen flow rate (N2) and the heating rate affect bio-oil, bio-char and gaseous products. These parameters were varied in the ranges of 5–50 °C/min, below 0.2–1 mm and 20–200 mL. min–1, respectively. The maximum bio-oil yield of 41.3wt% was obtained at a pyrolysis temperature of 600 °C, particle size between 0.2–0.5 mm, nitrogen flow rate (N2) of 100 mL. min–1 and heating rate of 5 °C/min. Liquid product obtained under the most suitable and optimal condition was characterized by elemental analysis, 1H-NMR, FT-IR and GC-MS. The analysis of bio-oil showed that bio-oil from Bifurcaria Bifurcata could be a potential source of renewable fuel production and value added chemicals.

Polycaprolactone based membranes for the degradation of diclofenac present in water samples using ZnO nanoparticles as the active agent

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3153-3161
Author(s):  
Marco Antonio Juárez Sánchez ◽  
Miguel Ángel Meléndez Lira ◽  
Celestino Odín Rodríguez Nava
Keyword(s):  
Zno Nanoparticles ◽  
Wastewater Treatment Plants ◽  
Active Agent ◽  
Heterogeneous Photocatalysis ◽  
Nano Particles ◽  
Electrical Characteristics ◽  
Unit Operation ◽  
Fields Of Study ◽  
Drug Contamination ◽  
Positive Results

AbstractDrug contamination in water is one of the current fields of study. Since 1990, the presence of drugs in drinking water has been a concern to scientists and public. In Mexico, these organic compounds are not efficiently removed in wastewater treatment plants; therefore, alternative methodologies have been studied that allow these compounds to have a high percentage of degradation or be completely degraded. One example of these techniques is heterogeneous photocatalysis which has obtained positive results in the degradation of drugs using ZnO nanoparticles. These are commonly selected for their electrical characteristics, even though they disperse in water and an additional unit operation is required to separate them from the liquid medium. To eliminate drugs with nano particles in a single stage, polycaprolactone-based membranes with adhered ZnO nanoparticles, by means of electrospinning, were prepared to degrade drugs such as diclofenac. The technique used has shown to efficiently break down diclofenac in 4 hours according to the capillary electrophoresis readings.

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